I can sort of do it with on my monitors with lots of volume and if I use my fuzz pedal in the chain. But my small 3w orange crush amp makes a buzzing sound whenever I try to use my fuzz pedal in it. And I can't seem to get the dynamic feedback sound. What is it that causes this and how can I recreate it?

In all seriousness though, if you're after dynamic feedback (I didn't listen to the track, so forgive me if I'm going the wrong way chasing an interpretation of words) I would reach for an amplifier that isn't shunting out all its headroom from the get go.

You want gobs of headroom left to work with, which generally translates to a more powerful amplifier. 3 watts can get you there, make no mistake, but this is analingus to surfing a mighty short swell and contrary to knee jerk opinion might demand a more attentive touch.

In all seriousness though, if you're after dynamic feedback (I didn't listen to the track, so forgive me if I'm going the wrong way chasing an interpretation of words)

I wouldn't even call it "dynamic feedback".. it sounds to me like the typical feedback you'd get with too much gain and the mic too close to the speakers.. it's all just high end squealing.. although since the audio is being captured on a video camera I can't be sure that the low end is missing but I'm not expecting there to be any.